Concentricity Guage
- Thread starter JohnW...ski
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bozo699
Gold $$ Contributor
Thank you.navyrad8r said:Wayne,
i got your back...i am sure the majority of the forum feels the same. As for the original post, i went with the 21st century CONCETRICITY GAUGE. i use a few of john's tools and all of them are top quality! he is very easy to work with and welcomes feedback, especiallywhen it improves his tools.
cheers,
Doc
Yes I agree about John, good equipment and very very easy to deal with I highly recommend him!
That's good Ed
Vern,
In reality the person I will not mention is correct, however in the shooting world and with the equipment we have for detecting and fixing yes there one and the same, although on a outside chance the centerline of the brass could be concentric but the outside (neck) could be oval for a lack of a better word and that would be runout however with the simple single indicator instruments we have to read all this either one would show a runout problem! That is why I said in my op that terminology is so important. Example I was discussing Jam with Boyd Allen a while back, very bright man and has become a good friend of mine, I was calling jam anything from just touching to all the way, not the correct terminology I found out and I now understand it is hard to answer someones question when there are several acceptable terminologies for one thing, I know know what jam is, because it was explained to me in a way I could understand it and once explained it made sense, one doesn't have to belittle someone to show them the errors of there ways, being sensable and respective of others feelings and still getting your point across is a sign of being a good teacher, if by chance you read this Boyd, thank you and thank you to all the others that have took the time to teach me something and make it understandable if I was having trouble. I try to do the same when I have some knowledge of something and am passing it on, there is nothing wrong with being a little humble,...thanks for listening.
Sincerely Wayne.
Killshot said:
And what does a pure ad hominem make you?
So really guys if I'm such an idiot answer me a simple question, how can you measure a "center point of an axis" with a single point indicator that rides on the OD? Does anybody have the balls to try to answer this question? Some how I doubt it.
I've noticed a trend here, nobody wants to engage on technical merit (other than mikecr, which I respect even if he doesn't agree with me or I don't' agree with him, I respect him). Personal attacks pretty much rule the day. Wayne's response to my first post in this thread was dismissive, condescending, and basically treated me like a dunce, but he is unwilling or unable to engage on technical merit, just his appeal to some authority as a maintenance man at an ammo factory (I love my maintenance guys at work so don't take that wrong). Of course I'm going to be condescending and arrogant in return, you get what you give. Really why does someone that has a different view, experience and education get such a shitty response, and based on purely technical grounds?
vern said:
This shows a perfectly concentric part that will show runout.
So the answer is maybe not!
BTW if you guys notice in that illustration has two opposed indicators, that is for an actual concentricity inspection, with a single point indicator you wouldn't know if it was an out of round condition or a concentricity error.
bozo699
Gold $$ Contributor
Stilesstiles said:Killshot said:
And what does a pure ad hominem make you?
So really guys if I'm such an idiot answer me a simple question, how can you measure a "center point of an axis" with a single point indicator that rides on the OD? Does anybody have the balls to try to answer this question? Some how I doubt it.
I've noticed a trend here, nobody wants to engage on technical merit (other than mikecr, which I respect even if he doesn't agree with me or I don't' agree with him, I respect him). Personal attacks pretty much rule the day. Wayne's response to my first post in this thread was dismissive, condescending, and basically treated me like a dunce, but he is unwilling or unable to engage on technical merit, just his appeal to some authority as a maintenance man at an ammo factory (I love my maintenance guys at work so don't take that wrong). Of course I'm going to be condescending and arrogant in return, you get what you give. Really why does someone that has a different view, experience and education get such a shitty response, and based on purely technical grounds?
vern said:
This shows a perfectly concentric part that will show runout.
So the answer is maybe not!
BTW if you guys notice in that illustration has two opposed indicators, that is for an actual concentricity inspection, with a single point indicator you wouldn't know if it was an out of round condition or a concentricity error.
I wasn't going to ever comment on another of your posts, but you just won't or can't drop it, listen Machinist I am not a grease monkey I am a $100000 Elect/tech I also am a licenced Millwright that I spent 20 years at and have been in this trade for almost 10 years so don't call me a maintenance drone, I didn't treat you like a idiot at all you are just the type that likes to fight, and swear, go to snipers hide forum if you want to fight and leave me alone!! I am no idiot and I think you are not as well but you are acting like one, your picture depicts exactly what I told Vern. If you want to meet me half way and get along with me GREAT if not then drop it! PERIOD! no one cares, I read all of your posts, took about three minutes, they were almost with the exception of the first one all argumentative??...Why?....You have some valuable info to teach, try doing it without being so arrogant! participate or leave, I doubt there are two people that would disagree with me on this whole site!
Wayne.
Stiles isn't it also true that a single indicator can be used to show eccentricity(+unknown TIR), if a centerline is chosen? That is, you pin a spot on both ends of a part to be measured, and indicate nearest center of the rotating length.
I believe this is the basis for H&H's claim as a concenticity gauge.
And I agree with your assessment of single indicating of a part which is pinned on it's OD, as RUNOUT(+unknown quantity of eccentricity).
I also believe that loaded ammo exhibiting low runout, as measured on a v-block runout gauge, is both straight and concentric, without a need for seperating the actual quanities.
Once deviation drops below 1thou(off bullet noses), there is no way to prove chambered affects to performance one way or another. So if .0005 of my deviation is eccentricity, and .00002 is runout due to wall thickness variance, or totally the other way around, it's still below .001 of deviation -from STRAIGHT. That's my line in the sand.
I believe this is the basis for H&H's claim as a concenticity gauge.
And I agree with your assessment of single indicating of a part which is pinned on it's OD, as RUNOUT(+unknown quantity of eccentricity).
I also believe that loaded ammo exhibiting low runout, as measured on a v-block runout gauge, is both straight and concentric, without a need for seperating the actual quanities.
Once deviation drops below 1thou(off bullet noses), there is no way to prove chambered affects to performance one way or another. So if .0005 of my deviation is eccentricity, and .00002 is runout due to wall thickness variance, or totally the other way around, it's still below .001 of deviation -from STRAIGHT. That's my line in the sand.
So to add on small factor into the question I posed.
Since we know that we are in reality dealing with a case and this has an inside and out side surface...
IF we could agree for the sake of argument that the neck was turned to a uniform thickness with a tolerance of .0001.
Would it be correct to expect that if the outside and inside were of the same dimensions and concentric to one another that the total runout should not be more than .0001?
BIG if's.
Would it also be correct that if the thickness were uniform, that if the outside showed runout that the same runout would have to apply to the inside?
Thanks for the info Wayne.
Since we know that we are in reality dealing with a case and this has an inside and out side surface...
IF we could agree for the sake of argument that the neck was turned to a uniform thickness with a tolerance of .0001.
Would it be correct to expect that if the outside and inside were of the same dimensions and concentric to one another that the total runout should not be more than .0001?
BIG if's.
Would it also be correct that if the thickness were uniform, that if the outside showed runout that the same runout would have to apply to the inside?
Thanks for the info Wayne.
CatShooter
stiles said:
Handloading is filled to the brim with the misuse of words. Node? We don't look for a node, cuz a node is a dead spot somewhere in the middle of the barrel, and it doesn't move - we look for the null or dwell at the end of the barrel. But everyone calls it a NODE (except me), and we all know what they mean.
Bolt thrust? There is no such thing - Bolts do not "thrust" - cases thrust, bolts stop them from going out the back of the action... But everyone calls it bolt thrust (except me), and we all know what they mean.
So when you are talking about reloading, to be arguing about semantics is silly, when we all know what the "intended" meaning of the word is... and we all know what the intended meaning of concentric is, when referring to cases or loaded cartridges.
That being said, to answer your comment: "I'm unaware of any concentricity gage marketed to handloaders"
Just drop "Concentricity gage" into Google, and you will find that handloaders are almost the ONLY people that concentricity gages are marketed to.
I am surprised that you didn't check that before posting your challenge to the world... Google is your friend.
stiles said:
You can call them what you want, but since the whole freakin' handloading industry calls them "concentricity gauges" , and since our language is dynamic... people determine the meaning of words and phrases, I think you lose this one.
You can be mad at me - everyone else is.
Meow
I don't have much education. I am just trying to get through life the best I can. I was a pretty fair cowboy before I got fat and lazy. I just want to enjoy my simple guns and do the best I can with them. I have learned a fair amount here.
If I want to call it a Concentricity Guage That's what I'm going to call it and I don't care what people think. It does what I want it to.
a lot of these fancy words are kinda nice but can you do anything useful like nurse a sick critter back to health? Maybe solve some money issues so I don't have to support freeloaders?
If I want to call it a Concentricity Guage That's what I'm going to call it and I don't care what people think. It does what I want it to.
a lot of these fancy words are kinda nice but can you do anything useful like nurse a sick critter back to health? Maybe solve some money issues so I don't have to support freeloaders?
BoydAllen
Gold $$ Contributor
It seems to me that these gauges seek to establish a reference axis in one of two ways, They either support the case or loaded round near the head and shoulder, or all along the body in a continuous V (a variation), or by supporting a loaded round near its head and near the tip of the bullet. Because of the difference in how rounds are supported, and the reference axis defined, the readings taken from any given round may differ. This does not mean that one is more correct than the other, just that they are different. If we assume that the body of a case is round, then there is no problem supporting the round entirely by contact with the case body to establish a reference axis. On the other hand, if we are of the opinion that cases may not be round at all points, including where gauges support them, then perhaps the axis defined by the alternate system may be viewed as potentially more constant. Within this latter category there are a couple of variants. Traditionally the back of the case has been supported a short distance in front of the extractor groove, in an area that is expanded by the pressure of firing. from this point forward the outside shape of the case is determined by the shape of the chamber, in combination with the sizing die, and the symmetry of the thickness of the case wall. The newest member of this category comes from Hornady, who chose to support the back of cases on the rim. The problem with this is that cases expand to fit the chamber somewhat unevenly, leaving the center of the rim slightly offset from the rest of the case. and since the rim plays no role in how the case lies in the chamber, using it for a point from which to establish a reference axis may be less desirable than using a part of the case that does. The old Bonanza, now Forster gauge may be adjusted to support the back of a loaded round on the rim, or some distance in front of it, depending on how the stop is adjusted. The H&H uses a short section of V block at the back of the case, in front of the rim. In practice I have found it better to adjust this piece so that it only touches cases at its back edge, nearest the head. This gauge is allows for a great degree of adjustment, and variation in setup. Another thing worth considering is how adaptable different gauges are to different cases. Most, but not all, work with a wide variety of case lengths and sizes. Hopefully no one is insulted by any of this, and the horse that I am beating has yet to expire.
I like the raw reading of TIR from a V-block, because I think the best we can do is make and chamber STRAIGHT ammo.
I believe a straight tube, holds good circularity, low surface deviations, and is concentric to the best our chambering allows.
Trying to separate measure to individual attributes, means looking at one while dismissing another.
Any shape can be centered(concentric),, an S-form,, a banana. But these aren't what we would expect to chamber well.
Concentricity means only that various points along an axis share a same centerline.
A circle, or a square,, or a triangle,,,or all three on an axis could be centered to read concentric.
So you could make ammo measure concentric by changing the center points(regardless of the ammo's actual shape).
This probably makes us feel better as concentricity gauges do produce very low readings, regardless of actual ammo shape.
Set the same ammo on a V-block, and good feelings are likely delayed for further efforts..
Before some declares all the little invalid deviations in runout, consider that ammo can consistently be made which indicates very low runout, and that this ammo would not register an indication at all on a concentricity gage. Those little deviations are as much an issue as anything else on chambering, and they can be corrected or discarded. Producing low runout is possible and conservative.
I believe a straight tube, holds good circularity, low surface deviations, and is concentric to the best our chambering allows.
Trying to separate measure to individual attributes, means looking at one while dismissing another.
Any shape can be centered(concentric),, an S-form,, a banana. But these aren't what we would expect to chamber well.
Concentricity means only that various points along an axis share a same centerline.
A circle, or a square,, or a triangle,,,or all three on an axis could be centered to read concentric.
So you could make ammo measure concentric by changing the center points(regardless of the ammo's actual shape).
This probably makes us feel better as concentricity gauges do produce very low readings, regardless of actual ammo shape.
Set the same ammo on a V-block, and good feelings are likely delayed for further efforts..
Before some declares all the little invalid deviations in runout, consider that ammo can consistently be made which indicates very low runout, and that this ammo would not register an indication at all on a concentricity gage. Those little deviations are as much an issue as anything else on chambering, and they can be corrected or discarded. Producing low runout is possible and conservative.
I use three totally different measuring devices to get the job done. One is rather crude, and is the very first one I did (learned a lot from it though).
Most of the time I use the NECO as the system works well for most anything I want to do, plus I have been known to use two and even three dial indicators with it at the sametime. (I know that's over the top). I like wand indicators for their built in accuracey, and repeatability. But I also found a small piece of granit in the trash (part of a junked gauge) to set it ontop of. Did it really help? I don't know, but it gave me a little more confidence.
Several years back (15?) a friend showed me a gauge plate he'd built to check cases with. It was so simple that I almost cried! It was a piece of 1/2" O-1 gauge stock with four holes center drilled in it with plain jane steel ball bearings epoxied into the holes. Not perfect by anymeans but a good start. A few days later I was going thru one of my tool boxes looking for something to make some measurments with on a surface plate, and there was one drawer full of tooling balls in all sizes and styles. I picked up a bag that had about a dozen .312" balls that were with the shoulder, and the idea of a new gauge plate hit me in the nose. I made a CAD drawing to get an idea how to space the balls, yet get a nice reading off the case. Then went strait over to the Bridgeport. Reamed several holes, and drilled and taped several others. To hold the indicators, I got a couple 5/16" shoulder bolts and turned the heads down to allow the indicator to fit on them. Worked like a dream for anything measuring the outside surfaces. Nothing moves except for the case and the indicator, so there's no built in lag from the ball bearings. After I got it done, I put three 10-24 shallow headed allen bolts on the bottom side to make it set on three point. Then went to the surface grinder and ground them parallel with the top. Then reground the top flat. It's so simple and cheap that it's scarey, and works very well. The plate could have just as easilly been made from a piece of CRS plate stock, and you can buy the tooling balls from MSC or McMaster Karr. The shoulder bolts are at the hardware store, but you could even make them from standard 1/4-20 bolts and use a lock nut on the bottom. Why fight it?
gary
Most of the time I use the NECO as the system works well for most anything I want to do, plus I have been known to use two and even three dial indicators with it at the sametime. (I know that's over the top). I like wand indicators for their built in accuracey, and repeatability. But I also found a small piece of granit in the trash (part of a junked gauge) to set it ontop of. Did it really help? I don't know, but it gave me a little more confidence.
Several years back (15?) a friend showed me a gauge plate he'd built to check cases with. It was so simple that I almost cried! It was a piece of 1/2" O-1 gauge stock with four holes center drilled in it with plain jane steel ball bearings epoxied into the holes. Not perfect by anymeans but a good start. A few days later I was going thru one of my tool boxes looking for something to make some measurments with on a surface plate, and there was one drawer full of tooling balls in all sizes and styles. I picked up a bag that had about a dozen .312" balls that were with the shoulder, and the idea of a new gauge plate hit me in the nose. I made a CAD drawing to get an idea how to space the balls, yet get a nice reading off the case. Then went strait over to the Bridgeport. Reamed several holes, and drilled and taped several others. To hold the indicators, I got a couple 5/16" shoulder bolts and turned the heads down to allow the indicator to fit on them. Worked like a dream for anything measuring the outside surfaces. Nothing moves except for the case and the indicator, so there's no built in lag from the ball bearings. After I got it done, I put three 10-24 shallow headed allen bolts on the bottom side to make it set on three point. Then went to the surface grinder and ground them parallel with the top. Then reground the top flat. It's so simple and cheap that it's scarey, and works very well. The plate could have just as easilly been made from a piece of CRS plate stock, and you can buy the tooling balls from MSC or McMaster Karr. The shoulder bolts are at the hardware store, but you could even make them from standard 1/4-20 bolts and use a lock nut on the bottom. Why fight it?
gary
I knew from the start that this was going to be a knock down drag out pissing match from the start. I came out of a field that built and did precision measurments, and have an idea what I need to get the job done. The real issue here is that there is no easy way to measure a loaded round without inducing some added error. Then we get into another issue that is just how close do we actually have to be? Fifty millionth's is a bit over the top, but I've done the arc second thing a lot. Very few if any of us has the equipment (let alone the knowledge to work in tenths of an arc second).
To build an accurate gauge, you must start out strait and square. Be it horizontal or vertical. 75% of the gauges we had built outside had to be reworked upon delivery, and many were junk from the start. Still easier the doing the alignments on a Devlieg jig mill (two tenths of an arc second in twelve feet, max error). Most of the better stuff these days uses either a laser or an encoder setup (.000050" scales). Centers that set atop a surface plate are usually scrapped to with in .000025" in a foot of travel. (lab grade). Always felt it was a waste of time, but the boss was always right! For reloading, anything that's in the .00025" range is more than good enough, and most everybody could get by quite well in the five tenths range. Lastly, when you playing around in the two tenths range we like to claim we are, you need a controlled enviorment. Tools that are inspected regularly, and are of good quality from the get go. Few of us will spend that kind of money (or can afford to)
gary
To build an accurate gauge, you must start out strait and square. Be it horizontal or vertical. 75% of the gauges we had built outside had to be reworked upon delivery, and many were junk from the start. Still easier the doing the alignments on a Devlieg jig mill (two tenths of an arc second in twelve feet, max error). Most of the better stuff these days uses either a laser or an encoder setup (.000050" scales). Centers that set atop a surface plate are usually scrapped to with in .000025" in a foot of travel. (lab grade). Always felt it was a waste of time, but the boss was always right! For reloading, anything that's in the .00025" range is more than good enough, and most everybody could get by quite well in the five tenths range. Lastly, when you playing around in the two tenths range we like to claim we are, you need a controlled enviorment. Tools that are inspected regularly, and are of good quality from the get go. Few of us will spend that kind of money (or can afford to)
gary
Without reviewing all this, has someone argued about the precision in our measure?
Seemed to me more a matter of method and terms to describe results.
Personally, .0005" resolution is all I need to see ~1thou or less TIR, and I know this is good enough to remove runout as a performance factor in ammo. If you can achieve this consistently, and maintain it over many reload cycles, then you're doing really good IMO.
I have fiddled with runout measure well below .0001 and found that surface profile of unbuffed brass interfered with reliable measure there.
Seemed to me more a matter of method and terms to describe results.
Personally, .0005" resolution is all I need to see ~1thou or less TIR, and I know this is good enough to remove runout as a performance factor in ammo. If you can achieve this consistently, and maintain it over many reload cycles, then you're doing really good IMO.
I have fiddled with runout measure well below .0001 and found that surface profile of unbuffed brass interfered with reliable measure there.
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